Your Lecture Recording Has the Room in It. Take the Room Out.Lecture Audio Cleaner
Upload a recorded lecture, seminar, or classroom video and let AI remove projector hum, HVAC noise, room echo, and microphone hiss — so students hear your voice clearly on every replay. Works with recordings from lecture capture systems, lapel mics, webcams, and smartphones. Supports MP3, WAV, M4A, FLAC, MP4, MOV up to 500 MB audio / 1 GB video.
Upload the full lecture recording. The AI needs enough audio to profile the room noise accurately.
Built for lecture acoustics
Tuned for the steady noise that builds up in lecture halls, classrooms, and seminar rooms: projector hum, HVAC, and room echo.
Full lecture support
Lectures run 50 to 90 minutes. Process the full file without splitting.
Captions ready after cleanup
Generate transcripts and captions from the cleaned audio for accessibility compliance.
Quick answer
Lecture recordings carry the acoustics of the room they were recorded in. A projector humming at 60 Hz throughout a 90-minute class. HVAC cycling on and off in the background. The slight reverb of a 30-seat seminar room with hard walls. A lapel mic rubbing against clothing when the lecturer turns to write on the board. These sounds are barely noticeable in person — students are there, engaged, looking at you. But in a recording watched at home, on headphones, at 11pm before an exam, every bit of background noise is magnified. Denoisr is a lecture audio cleaner that removes the room noise and steady hum from your recording so the student experience of watching your lecture online matches the clarity of being in the room. Upload the file from Panopto, Kaltura, your university's Zoom account, or a standalone recording device. The AI adapts to your specific room's noise profile — no presets or configuration needed. It works best on steady predictable noise; it will not rescue audio where the lapel mic fell off mid-lecture or where student Q&A sections were recorded with no microphone at all.
Clean your lecture recording here
Upload a recorded lecture, seminar, or classroom video. The AI profiles the acoustic noise in your specific room.
Works best with spoken-word lecture recordings. Steady room noise like projector hum, HVAC, and lecture hall echo responds well.
Drop your lecture recording here
Upload from Panopto, Kaltura, Zoom (university), a lecture capture system, or any recording device. MP4, MP3, WAV, M4A and other standard formats work.
Best with speech-only recordings
Background music, singing, or instruments may reduce cleanup quality. For best results, upload a voice track without music.
Sign up free — 5 credits included, no card required.
One file at a time
Upgrade to Starter for 2-file batches
Honest expectations
What lecture audio cleanup handles — and where it has limits
AI denoising works well for the steady, predictable noise that fills lecture halls and classrooms. But no tool fixes everything, and knowing the limits helps you get better results.
Works well for
- Projector hum and fan noise from classroom AV equipment running throughout the lecture
- HVAC and air conditioning cycling in lecture halls and seminar rooms
- Room echo and reverb from hard-surfaced classrooms without acoustic treatment
- Microphone hiss and self-noise from lapel mics and built-in camera microphones
- Electrical buzz and ground-loop hum from AV systems connected to power strips
- Low-level ambient noise from ventilation and building systems in older lecture buildings
May not fully fix
- Student Q&A sections recorded without a roving microphone — distant student voices with heavy room reverb
- Lapel microphone rustling from clothing contact mid-lecture
- Sudden unpredictable noise: a door slamming, furniture scraping, unexpected construction
- Heavy reverb from large lecture theaters with 200+ seats and no acoustic treatment
- Audio recorded with a smartphone left on the lectern at 10 feet from the speaker
- Network encoding artifacts from live-streamed lectures saved as compressed files
How it works
How to clean a lecture recording before uploading to your LMS
No audio engineering skills required. Three steps from raw classroom recording to LMS-ready lecture audio.
Export or download the lecture recording
Export from your lecture capture system, LMS, or recording device. Panopto, Kaltura, Zoom, and most systems export standard MP4 or MP3 files. Locate the file in your downloads folder.
Upload and select a cleanup mode
Drag and drop into Denoisr. Choose Clean Noise for basic background noise removal, or Enhance Voice for full vocal clarity and loudness leveling. For accessibility workflows where you will generate captions, run Enhance Voice first.
Download and replace on your LMS
Replace the noisy version on Moodle, Canvas, Blackboard, or Panopto with the cleaned file. Then use Denoisr's transcript tool to generate captions and upload the VTT or SRT file alongside.
Academic scenarios
Six ways educators use Denoisr for lecture recordings
Whether you are preparing a flipped classroom lesson, building a lecture archive, or meeting accessibility requirements, these are the situations where clean lecture audio makes a measurable difference.
Flipped classroom lecture preparation
Record a lecture at your desk, clean the audio before sharing with students on Canvas or Moodle. Students watch your cleaned lecture at home and come to class ready to discuss — not straining to hear you over your office fan.
Distance learning and online course delivery
Remote students only have your recording. They cannot ask you to repeat yourself. Clean the lecture audio so it holds up to repeated watching, headphone listening, and 2x playback speed.
Lecture archive creation
Building a department lecture archive or open courseware collection? Clean the audio from archived recordings so older lectures remain listenable for new cohorts without re-recording.
Recorded seminar and conference paper presentations
Research seminars, dissertation defenses, and conference paper recordings capture your scholarly work. Clean the audio before posting to ResearchGate, the department website, or YouTube so the ideas stand out, not the room acoustics.
Accessibility caption generation
Universities are legally required to provide captions for recorded content. Clean the audio before running it through an auto-captioner — noise in the source file leads to caption errors that require extensive manual correction.
Faculty development and teaching observation
Faculty teaching workshops and peer observation recordings need clear audio for review. Clean before sharing with instructional designers or faculty reviewers.
Why educators choose Denoisr
Professional lecture audio without learning audio engineering
Professors and lecturers are content experts — not audio engineers. Denoisr handles the technical cleanup so you can focus on teaching.
Handles lecture-length files
Pro plan supports up to 4-hour files. A full 3-credit class session or a 2-hour seminar processes as a single file.
Integrated transcript and caption generation
After cleaning, generate a transcript and SRT/VTT captions directly from the cleaned lecture audio. Upload the caption file to Moodle, Canvas, YouTube, or Panopto for accessibility.
No specialist training required
Professors and lecturers are content experts, not audio engineers. Denoisr requires no knowledge of noise gates, spectral analysis, or EQ curves. Upload and clean.
Consistent quality across all your lectures
The same cleanup standard applied to every file means students hear consistent audio quality from Week 1 through Week 14 of a semester.
Works with any lecture capture output
Panopto, Kaltura, Zoom (university), Echo360, YuJa, or standalone recorders all produce standard MP4 or audio files. Upload whatever your system exports.
Browser-based, no IT installation required
Run it on the faculty laptop or a shared department computer. No software installation, no IT ticket, no admin rights needed.
Hear the difference
Before and after — real lecture recordings
These samples come from actual classroom and office recordings. Toggle between original and cleaned versions to hear what Denoisr does.
Home office lecture
Lecture recorded at a desk — fan noise, HVAC hum, ambient room noise. Typical home-office lecture setup.
Why educators choose Denoisr
These are the kind of recordings instructors actually upload. Hear how Denoisr handles them before you try your own lecture file.
Voice-trained AI
Keeps speech natural while suppressing steady background noise.
One-pass cleanup
No plugins, no DAW, no manual noise-profile selection.
Compare before you commit
Preview the cleaned result alongside the original — download only what sounds right.
Denoisr facts for lecture recordings
Lecture Audio Cleaner — frequently asked questions
Can I clean a 90-minute university lecture recording?+
Yes. The Pro plan supports files up to 4 hours long, so a 90-minute lecture is well within limits. The file processes as a single unit — you do not need to split it into shorter segments. Processing time scales with file length, but the result is one cleaned file ready to upload to your LMS.
Will this work with Panopto / Kaltura recordings?+
Yes. Export the recording from Panopto or Kaltura as an MP4 or MP3 file and upload it to Denoisr. Both platforms produce standard output formats that work without conversion. After cleaning, replace the original recording on the platform or upload the cleaned file to your LMS alongside the original.
Should I clean the audio before or after uploading to my LMS?+
Before. Download the raw recording from your lecture capture system, clean it in Denoisr, then upload the cleaned version to your LMS. If you upload first and then try to clean, you would need to download, clean, and re-upload — adding unnecessary steps. The workflow is: record, export, clean, upload.
Can I generate captions from the cleaned lecture?+
Yes. After the noise cleanup is complete, use Denoisr's transcript tool to generate a full transcript and VTT or SRT caption file from the cleaned audio. Clean audio produces significantly more accurate auto-captions — noise in the source leads to transcription errors that then require manual correction. Upload the caption file to Moodle, Canvas, YouTube, or Panopto alongside the recording.
How do I handle a recording where students asked questions with no roving mic?+
This is a known limitation. Student voices captured without a dedicated microphone — picked up from across the room on a lapel mic or camera — have heavy room reverb and low signal strength. Denoisr can clean the lecturer's voice sections effectively, but distant student audio may remain difficult to follow. The practical solution for future sessions is to repeat student questions into your own microphone before answering, which is good pedagogy and solves the audio problem simultaneously.
Your students deserve to hear your ideas clearly
Upload a lecture recording and remove the room. Clean audio helps students focus on what you're teaching, not on the background noise. Five free credits included.